“…The spatial nature of economic activities and variables was first put into examination in the early 1950s and spatial equilibrium analysis featured the literature of that time (Enke 1951 andSamuelson 1952). Since the 1960s, spatial analysis in economics has greatly expanded its range of study, varying from spatial equilibrium models for trade, transportation and labor markets, to various kinds of more general models for environmental, energy, and geographical and regional economic analyses, e.g., see Labys, Takayama and Uri (1989), Labys and Yang (1991), van den Bergh, Nijkamp and Rietveld (1996), Nijkamp (1986), and Bockstael (1996).…”